A. Infectious diseases, previously the leading cause of death, disminished dramatically due to improvements in sanitation and antimicrobial drugs and vaccine implementation. B. Global warming led to an increase in vector-borne diseases such as Lyme Disease, as the summers became warmer. C. Global warming led to a decrease in colds and influenza, which were typically only prevalent in winter. What has been the greatest change on public health over the past century as a result of public health survelilance? Multiple Choice Infectious diseases, previously the leading cause of death, diminished dramatically due to improvements in sanitation and antimicrobial drugs and vaccine implementation. Giobol warming led to an increase in vector-borne diseases, such as Lyme disease, as the summers became warmer. Global warming led to a decrease in colds and influenza, which were typically only prevalent in wintec. .